Problem: In her history class, Gabriela took 4 tests. Her scores were 78, 82, 88, and 96. What was her average score on the tests?
The average is the sum of her scores divided by the number of scores. There are 4 scores and their sum is $78 + 82 + 88 + 96 = 344$ Her average score is $344 \div 4 = 86$.